Brake testing machine



Sept. 6, 1932.

H. w. LANGBEIN BRAKE TESTING ncanm Original med oct. 29. 1925 2 Shuts-Sheet 1 Sept. 6, 1932. H. w. LANGBEIN 1,375,742

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Original Filed Oct. 29, 1925 2 Sheets-Sh et 2 II i V I Q 7 I. .7 6'

29 .umm lllllllll f/aro la M44 be/b 5) W H T'TOE/VEX Patented Sept. 6, 1932 HAROLD W. LANGBEIN, OF LOS ANGELES,

CALIFORNIA, ASSIGNOR TO BRAKE SYN- CHROMETER ('10., OF BOSTON, MASSACHUSETTS, A COREORATION OFMASSACHUSETTS BRAKE TESTING MACHINE Originalapplicatibn filed October-.29, 1925, SerialNo. 65,604. Divided and'this application filed June 1,

1929. Serial Thisapplication is a division of my patent for Brake testing machine, No. 1,746,780,

granted February 11, 1930.

This invention particularly pertains to a device for vfacilitating adjustment of the brakes of motor vehicles, and has as its .pri-

mary object the provision of a means whereby the relative brake pressures of a pluralityof vehicle brakes simultaneously applied may be ascertained to the end of enabling any adjustments of one or more of the brakes as may be necessary in order to establish equalization of brake pressures.

Anotherv object is to provide a means '15 whereby the relative braking effect ofat least two vehicle brakes may be coincidently determined witha high degree of accuracy,and whereby the braking action may be readily tested without the necessity of road tests as is now generally practiced.

Another object is to provide a brake testing mechanism by means of which the braking action on the wheels of a vehicle maybe ascertained while the vehicle is stationarily supported in a'rack, both as to equalization of brake pressures on two or more wheels,

and as to the set of the brakes in effecting stopping of the vehicle in a predetermined distance oftravel on the full application'o the brake with the vehicle moving atagiven speed. I

A further object is to provide a brake test- .ing mechanism of the above character which is simple in construction, eflicient in operation, which is not liable to get out'of order,

and which will enable rapid determination of braking operations in such manner as to effect a great economy and saving of time in accomplishing proper adjustment of the brakes.

With the foregoing objects in view, together with such other objects and advantages as may subsequently appear, the invention resides generally in the provision of a rack embodying rollers on which the wheels of a vehicle may be supported, together with separate and independent sources of power for coincidently propelling at least two brake-equipped wheels of a vehicle, together with independent means actuated by said sepr 1y,A mar; (Fig.1)

of power.

arated sources of power for indicating the resistance or load imposed on the wheels by the application of their brakes, andalso resides in a construction whereby the sources ofpower may be thrown out of operation and the apparatus utilized in part in determining the -efiective braking action of the vehicle brakes in bringing the vehicle to rest from a predetermined speed.

The invention further resides in the parts .and in the construction,combination and arrangement of'parts hereinafter described and claimed, and illustrated by way of example'in the accompanying drawings, in which:

Fig. 1 is a plan view depicting a preferred embodiment of the invention with parts shown in horizontal section and with portions thereof shown diagrammatically.

Fig. 2 is a detail in vertical section as-seen on the line 22 of Fig. .1.

Fig. .3 isadiagrammatic view of an appliance for indicating the effective brake action in stopping the vehicle.

Fig; 4 is a detail in section asseen on the line- 4-4 of Fig. '2.

"Fig. 5 is a diagrammatic plan view illustrating a modification ofthe invention.

Referringto the drawings more specificalindicate apair of electric motors constituting two independent sources The drive shafts C and D of the motors are aligned and passed through bearings-E and 'F and carry rollers G and H, the motors A and B being interposed between the rollers, and the rollers G and H being spaced apart horizontally a distance corresponding to the regulation span of the wheels of amotor vehicle. The rollers G and H are adapted to be driven independentlyby the motors A and B. Arranged in alignment with the rollers G and H are corresponding idling rollers I and J journalled in suitable bearings and spaced from the rollers Grand H, respectively. The pairs of rollers G and I, and and J, are arranged to support the'wheels Z of amotor vehicle as shown in Fig. 2, and "as a means for aflt'ording a run on the rollers for the vehicle wheels; the peripheries of the rollers are concave.

The motors A and B are complementary and are preferably of" the three-phase type and are connected to the usual conductors in an electrical circuit, the motors A and B being arranged in parallel relation and being operated by electrical current from a common source passing through leads a, b and c, fitted with the usual switch (1, which leads connect with the motor A through conductors e, f and g and. with the motor B through conductors h, z and 7'.

In carrying out the invention, ammeters indicated at k and Z are arranged in the conductors e and h, respectively, independently for indicating the load imposed on the motors A and B.

In the form of the invention illustrated in Fig. 1, the drive shafts G and D of the motors A and B are adapted to be placed in and out of interconnection through the medium of a shaft K extending in alignment with the shafts O and D, between which shaft K and shafts C and D are interposed suitable clutches L and M of the positive type. Each clutch is here shown as embodying a member N fixed on the sh aft K and a member splined on the motor drive shaft, the members 0 being adapted to be simultaneously shifted to position them in and out of engagement with the clutch members N by means of operating levers P and Q fulcrumed at R and Shaving yokes engaging sleeves T carried by the shiftable clutch members 0. The outer ends of the levers P and Q are connected by links U and V to a rod W in such manner that a pull on the rod W will rock the levers P and Q in opposition to springs X to effect disengagement of the clutch members.

The shaft K is journalled in spaced bearings Y, and fixed on the shaft K between the bearings is a fiy-wheel 3.

The clutches L and M are disengaged when employing the device in testing the vehicle brakes to ascertain the relative braking effect thereof, in which instance the motors A and B are simultaneously operated to drive the rollers G and H independently. The clutches are engaged to effect a direct connection between the rollers G and H through the motor drive shafts and the shaft K when using the device as a means for determining the action of the brake in stopping :1 vehicle, in which instance the rollers G and H are driven through the motive power of the vehicle transmitted through the wheels supported on the rollers.

In the form of the invention shown in Fig. 5, a pair of rollers 5 and 6 are driven from independent sources of power indicated at 7 and 8 through the medium of drive shafts 9 and 10, which drive shafts are fitted with dynamometers 11 and 12 of any suitable construction, whereby the loads on the wheels or rollers 5 and 6 may be independently ind cated. A pair of rollers 13 and 14 are arranged in alignment with the rollers 5 and 6 and spaced therefrom and are operable independently thereof, the rollers 13 and 14 being fixed on shafts 15 and 16 extending in ali nment toward each other and adapted to e disposed in and out of interconnection through the medium of a shaft 17 and clutches 18 and 19 interposed between the shaft 17 and the shafts 15 and 16. The clutches 18 and 19 are adapted to be coincidently thrown in and out of their engaged position by means of levers 20 and 21. The shaft 17 is fitted with a fly-wheel 22.

Ineach of the forms of the invention shown, means are provided for enabling the determination of the distance at which a vehicle travels after the full application of the brakes before coming to rest, which means is illus' trated diagrammatically in Fig. 3 and includes a timer arranged in an electrical cir- -29 meshing with a gear 30on a shaft 31 formed in continuation of the motor drive shaft D carrying the roller 8, as shown in Fig. 1, or in continuation of the shaft 16 carrying the roller 14, as shown in Fig. 5,

whereby the gear 30 may be driven to actuate the timer when the rollers are impelled by driving the vehicle wheels supported thereon.

In the operation of the preferred embodiment of the invention shown in Fig. 1 to effect testing of the brakes of a vehicle, the vehicle is positioned with its brake carrying wheels supported on the rollers G, I, Hand J with the Vehicle clutch mechanism disposed in neutral. The clutches L and M are then thrown out of engagementand the motors A and B set in operation by closing the switch d, thereby ,effecting independent driving of the rollers G and H and of the vehicle wheels supported thereon. By applying the vehicle brakes the movement of the vehicle wheels will be retarded, thereby effecting a drag on the rollers G and H and imposing increased loads on the motors A and B, which loads will be indicated by the ammeters 7c and Z.

In event the braking effect ofthe vehicle brakes are'equal, the load on the motors A and B will be equal, and accordingly, the readings of the ammeters will correspond, thus indicating to the observer that the pair of brakes being thus tested are of equal brakin g action. In event of any inequality of the braking effect of either of the brakes being tested there will be a variance in the load imosed on the motors A and B which variance will be indicated by the ammeters so that the operator may make the proper adjustments to the end of equalizing the brake actions. In this manner proper relative adjustment of the brakes may be easily and quickly effected.

In like manner, in the operation of the embodiment of the invention shown in Fig. the clutches 18 and 19 are thrown out of engagement so that the rollers 13 and 14 may be idle relative to each other whereupon on setting 15 the motors 7 and 8 in operation the relative effect of the vehicle brakes may be ascertained.

It will be understood that the motors are balanced in regard to speed and current so that the readings of the ammeters will correspond on sub ecting the motors to corresponding loads.

It will be observed that the impelling rollers are connected directly to the motor driven shafts. This serves to minimize variations due to friction or lost motion and thus insure a high degree of accuracy in effecting tests.

In the operation of the invention to determine the effectiveness of the brakes in stopping movement of a vehicle travelling at a predetermined speed and to ascertain the distance traversed by the vehicle after full application of its brakes, the clutches L and M in the arrangement shown in Fig. 1, of the clutches 18 and 19 in the arrangement shown in Fig. 5 are disposed in en agement so as to efl'ect a positive connection etween opposite rollers and to dispose the fiy-wheel in the connection. The wheels of the motor vehicle resting on the rollers are then set'in motion by operation of the vehicle motor, and are brought up to a predetermined speed according to indications of the vehicle speedometer, whereupon the vehicle brakes are fully applied by operation of the brake lever 26.

The application of the vehicle brakes retards rotation of the vehicle wheels and acts through the vehicle wheels to retard rotation of the rollers G and II and finally the flywheel 3, by reason of its weight and momentum or kinetic energy at a given speed will thus serve as a means of affording the equivalent of momentum or kinetic energy of a vehicle when traversing a roadway at a given speed, so that in testing the effectiveness of the vehicle brakes in bringing the vehicle to a stop substantially the same condition will be created in the testing machineas would be present in making a road test. This operation of the brake lever closes the switch p so that the timer 25 (which is being rotated from the roller being driven by the vehicle wheels) will effect a make and break of the 65 electrical circuit through the solenoid 9 so vehicle from its position on the that the latter will be energized intermittently and be caused to actuate the counter 27 on each revolution of the application of the brakes results in stoping the vehicle wheels, driving of the ti .ier will also be discontinued so that the operator, by referring to the counter 27, may calculate the peripheral distance traversed by the vehicle wheels which distance represents the lineal distance of travel that would have been traversed by the vehicle in a road test. In determining this distance of travel the diameter of the vehicle wheels and the weight of the vehicle will be taken into consideration together with the indications of the counter 27 according to a suitable chart.

It will be understood that in thus testing vehicles having wheels of different diameters, gears 29 and 30 of proper relative diameters in relation to the diameter of the vehicle wheel will be employed.

As a means for facilitating removingthe rollers, means are provided whereby opposite rollers may be locked against rotation which is here shown as accomplished by inserting pegs 35 in openings 36 formed in the side faces of the rollers, as shown in Fig. 4, in such manner that the pegs will project in front of the roller supports to limit their rotation.

\Vhile I have shown and described the specific embodiment of my invention, I do not limit myself to the exact details of construction and arrangement shown but may employ such changes and modifications as come within the spirit and scope of the invention as set forth in the appended claims.

I claim as my invention:

1. In a machine for testing the brakes of motor vehicles a pair of complementary electric motors constituting separate and independent sources of power, said motors being arranged with their drive shafts in alignment; rollers fixed to said drive shafts; a pair ofidle rollers cooperating with said first named rollers to form a support for opposite wheels of a motor vehicle whereby each of said wheels may be driven independently by said motors; and a pair of independent ammeters for separately indicating the loads imposed on said motors.

2. In a machine for testing the brakes of a motor vehicle: a plurality of,,roller supports for the wheels of a vehicle; a motor for rotating each roller-support; a common source of energy for -said motors; and ameter between said source and each of said motors whereby to separately indicate the load on said source as effected by resistance on each of the several roller supports upon an application of the brakes carried by the wheels of the vehicle.

3. In a device of the character described, the combinationof: a rotary support for the opposite wheels of a motor vehicle adapted the timer 25. WVhen tobe rotated on propulsion of the vehicle wheels; means actuated by said rotary support controlled by the vehicle brake operating lever enabling the determination of the effectiveness of the vehicle brakes in stopping the vehicle; and means independent of said lastnamedv means for determining the relative braking action of the vehicle wheels.

4. In a machine for testing the brakes of a motor vehicle: two pairs of rollers for supporting opposite Wheels of a vehicle, the rollers of each pair bein independent of each other; a pair of complementary electric motors, one of said motors being directly connected to a roller of one of the pairs and the other motorbeing directing connected to a roller of the other pair; a meter between eachof said motors and its source of energy whereby to separately indicate the load on said motor asieflectei by resistance on each of said rollers upon theapplication of the brakes carried by the wheels of the vehicle; and means for limiting rotation of a roller in each pair.

5. In a machine for testing motor vehicle brakes, the combination of: a plurality of roller means adapted to support the wheels of a vehicle to be tested; independent motors associated with each of said roller means and adapted to rotate said wheels independently;

means for connecting said roller means so that said roller means will be synchronously rotated; means for indicating the loads on said. motors when said roller means are independently rotated; and testing means for determining the effectiveness of said brakes in stopping said vehicle, said testing means being operable when said roller means are synchronously rotated.

6. In a machine for testing motor vehicle brakes, the combination of; roller means adapted to support the wheels of a vehicle to be tested; independent motors associated with said roller means and adapted to rotate said wheels; clutch means for connecting said roller means so that they chronously, said clutch means being readily disconnected to permit independent rotation of said roller means; means for indicating the loads on said motors when said wheels are independently rotated by saidmotors; and means for determining the efl ectiveness of said brakes in stopping said vehicle.

7. In a machine for testing motor vehicle brakes, the combination of: pairs of rollers adapted to support the wheels of a vehicle, one roller of each of said pairs having a relatively long axle; a motor associated with each of said axles and adapted to rotate a wheel of said vehicle; clutch means adapted to connect said axles so that they will rotate in unison, said clutch means being readily disconnected to permit the independent rotation of said axles; means for indicating the relative breaking actions of said will rotate synwheels when said clutch means is disconnected; and means for determining the effectiveness of said brakes in stopping said vehicle when said clutch means is connected.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 27th day of May, 1929.

HAROLD W. LAN GBEIN.

CERTIFICATE OF CORRECTION;

Patent No. 1,875,742 Septembe'rb; 1932.

HAROLD W. LANGBEIN.

it is hereby certified that the above numberedpatentfl waserroneously issued to "Brake Synchrometer Co., olBoston, Massachusetts, a corporation of Massachusetts," as assignee of the entire interest in said invention, whereas said patent should have been issued to the inventor said "Langbein".. as shown by the records of assignments in this office; and that the said Letterslatent should be read with this correction therein that the same may, conform to the record of the case in the Patent ()fiicm 7 i Signed and sealed this 21st day of February, A. D. 1933.

M. J. Moore,

(Seal) Acting Commissioner of Patents. 

